We continuously run layout tests on our FYI waterfall to prevent integration problems with Chromium.

On test failures, the bots compare the results of V8 Tip-of-Tree with Chromium's pinned V8 version, to only flag newly introduced V8 problems (with false positives <<5%). Blame assignment is trivial as the linux release bot tests all revisions.

Commits with newly introduced failures are normally reverted to unblock auto-rolling into Chromium. In case you break layout tests and the changes are expected, follow this procedure:

1. Land a Chromium change setting NeedsManualRebaseline for the changed tests (more).
2. Land your V8 CL and wait 1-2 days until it cycles into Chromium.
3. Switch NeedsManualRebaseline to NeedsRebaseline in Chromium. Tests will be automatically rebaselined.

Please associate all CLs with a BUG.